Since the initial jpackage in JDK-14, MacAppStoreBundler has existed but MacAppStoreBundler.isSupported() is hardwired to return false, so in effect this is all dead code.
It was thought that we would need this bundler, separate from MacPkgBundler, to create artifacts suitable for the mac app store, but this is not really the case, all that is really needed is different certificates.

Whether or not we introduce further syntax to express desire to sign package for mac app store, it should not be done in the form of a new package type